Prague Metro Line V Extension, Section VA Dejvice – Motol

Prague Metro Line V Extension, Section VA Dejvice – Motol

Project owner:
Dopravní podnik hl. m. Prahy a. s.
Sokolovská 217/42
190 23 Praha 9

Project owner’s representative:
Inženýring dopravních staveb a. s.
Na Moráni 3
128 01 Praha

Contractor:
Sdružení metro V.A (Dejvická–Motol) consortium
consisting of:
Metrostav a. s.
Hochtief CZ a. s.

Designer:
METROPROJEKT Praha a. s.,
nám. I. P. Pavlova 1786/2
Praha 2

Contractor for geotechnical monitoring:
ARCADIS Geotechnika a.s.
Geologická 4 
152 00 Praha 5

INSET s.r.o.
Novákových 6
180 00 Praha 8

Construction period:
2010 - 2014

Basic data:
laying-out length of the section: 6,134m
minimum longitudinal gradient: 39,5 ‰
minimum radius of a horizontal curve on running track: 500m
number of stations: 4
anticipated travel time from Dejvická station to Motol station: 7,5min.
minimum train headway: 90s

Project description:
The operating section VA of the metro line is 6.12km long; it contains three mined stations (Červený Vrch, Veleslavín and Petřiny) and one cut-and-cover station (Motol).

Červený Vrch station
Červený Vrch station is located under Evropská Street. It is designed as a mined, single-span structure with one cut-and-cover concourse. The depth of the intermediate platform under the terrain surface on the station centre line is 27m. The track centre distance is 13m.
The concourse, which is accessible from the eastern front end of the station via three escalators, is located in the intersection with Horoměřická Street, with a link to a terminal for urban and suburban bus lines under preparation. There is a subway under Evropská Street, making also direct transfer to the tram line running along this street possible.
The western part of the platform is connected to the surface in a barrier-free manner by means of a pair of personnel lifts and an escape staircase, which are located in a common vertical shaft. The lifts lead to the subway under Evropská Street, near Arabská and Kamerunská Streets.

Visualisation of Červený Vrch station


Veleslavín Station
Veleslavín station with its centre approximately under Evropská Street is located in the space between a current Czech Railway’s track and the eastern section of K Červenému Vrchu Street. The station is designed as a three-span structure mined shallow under the surface, with an intermediate platform 19m under the surface. The track centre distance is 15m. The western end of the platform adjoins the cut-and-cover structure housing three escalators and a lift to an underground concourse. The locations of the station, concourse and individual exits are designed with the aim of allowing direct links to a temporary bus terminal, tram stops on Evropská Street and, at the same time, responding in advance to the anticipated modernisation of the Czech Railways’ track including a station on the high-speed rail line.



Visualisation of Veleslavín station


Petřiny Station
The station is designed as a mined, single-span structure with an intermediate platform at 37m under the terrain surface. The track centre distance is 14.7m. A dead-end tail track housed in a single-track tunnel located between the two running tunnels is connected to the station in the direction of Motol station. It is in the location where dead-end track terminates that all of the three tunnels are interconnected and a gallery designed to house the main ventilation plant ending in a ventilation shaft will be driven. The southern part of the platform is connected to the surface in a barrier-free manner by means of a pair of lifts and an escape staircase, which are located in a common vertical shaft, ending in an at-grade entrance structure. The exit from the northern end of the station to the concourse is designed to be via three escalators running through a mined escalator tunnel.

Visualisation of Petřiny station

Motol Station
Motol station is a shallow-located cut-and-cover station with side platforms. The glazed station roof structure allows daylight to illuminate the platform. The two-storey station structure is designed in cast-in-situ reinforced concrete. The concourse is on the under-the-platform level. A subway under Kukulova Street with exit ramps ending at two opposing bus stops and on hospital grounds links to the concourse.

Visualisation of Motol station

Running tunnels
Running tunnels between stations are to be mined nearly throughout their lengths. They are mostly designed as single-track structures, with the exception of the vicinity of Motol station, where double-track tunnels will be driven.
The single-track running tunnels are assumed to be driven by two Herrenknecht-manufactured Earth Pressure Balance TBMs. Both proposed machines are 6m in diameter, with 8m long shields and about 80m long back-ups.
From Motol station toward Petřiny station the alignment turns north through left-hand curves to reach the space of Petřiny station. The initial tunnel section is an about 770m long, mined double-track structure, constructed using the NATM. Two about 500m long single-track tunnels continue from the location of the TBM assembly shaft.
Behind Petřiny station the alignment turns north-east through a curve and, at the same time, descends to Veleslavín station. The maximum longitudinal gradient within the section is 38.7 ‰. The total length of the mined single-track tunnels with cross passages amounts to approximately 1,070m.
The alignment further proceeds through two about 800m long, mined single-track tunnels to Červený Vrch station. The mined running tunnels are interrupted at the distance of 150m behind the station by an about 50m long cut-and-cover structure, housing a ventilation plant, with a ventilation shaft located between the two single-track running tunnels. The maximum longitudinal gradient within the section is 35 ‰.
Behind Červený Vrch station, the metro route proceeds under Evropská Street through two 1,760m long, mined single-track running tunnels, ending in the space of stabling tracks of the current Dejvice terminal station. The running tunnels descend at the maximum gradient of 39.5 ‰. A common cut-and-cover structure, housing a converter station and ventilation plant with a ventilation shaft is designed to be built in this section.

Geotechnical conditions:
The pre-Quaternary bedrock in the area of operations consists of the Barrandian Early Palaeozoic rocks (the Ordovician – Silurian period), represented first of all by shale, sandstone, siltstone and greywacke, locally with quartzite interbeds. A minor proportion is also formed by Ordovician volcanism rocks, consisting mainly of basalt tuffs and tuffites and basaltic agglomerates. The Ordovician period is represented by strata distinctive of Prague geology, namely the Šárka, Dobrotiv, Libeň, Letná, Vinice, Záhořany, Bohdalec, Králův Dvůr and Kosov strata. The Liteň Silurian strata rise from under the Cretaceous bed in the vicinity of Motol station.
Other rocks of the pre-Quaternary bedrock are of the Mesozoic age; they originated in the Upper Cretaceous period (the Peruc, Korycany and Bílá Hora strata). These rocks are represented by clays and claystone with black pigment, sandstone, agglomerates and, in upper layers, marlstone.
The Quaternary cover is first of all represented by deluvial, deluviofluvial, aeolian and fluvial terrace deposits.
From the hydrogeological point of view, it is necessary for the Upper-Cretaceous rocks to take into account the existence of separated aquifers in individual strata, featuring mostly fissure permeability up to intrinsic-fissure permeability.

Works progress
December 2009 saw the project owner, the Prague Public Transit Company Inc., award the contract to the Sdružení Metro VA (Dejvice Station-Motol) consortium, consisting of Metrostav a. s. and Hochtief CZ, a. s., for implementing the metro line VA extension from Dejvice station (excluding) to Motol station (including).
Ceremonial tapping of the foundation stone into place took place on 14/05/2010, with Prague’s lord mayor present; the excavation of access tunnels started in June 2010, with the commencement of driving using tunnel boring machines planned for the spring of 2011. 

Till now the following work on underground structures has been carried out (as of 01/01/2011):
Motol – sinking of the assembly and ventilation plant shaft has proceeded
The excavation of access and ventilation tunnels for Petřiny station, the tunnel for the dead-end track behind the station, the ventilation shaft and the TBM assembly chamber has been finished.
On the Veleslavín station site nearly all drifts for sewerage diversions have been finished.
On the Červený Vrch station site, the excavation of the construction trench for the portal has been completed, part of the access and ventilation tunnel has been driven and the ventilation shaft sinking has been finished.

Photo Gallery


Metro Line A extension - section VA layout


Section VA – longitudinal section


Portal of Markéta access tunnel (the Vypich site)


Excavation of the bottom of Markéta access tunnel (the Vypich site)


Portal of Kateřina access tunnel


The NATM excavation of the double-track tunnel in the direction of Motol station


Starting breakouts for EPB TBMs in the assembly shaft


Petřiny station – installing excavation support for the ventilation plant cavern